diff --git a/js/canvas.ts b/js/canvas.ts
index c373577..680790b 100644
--- a/js/canvas.ts
+++ b/js/canvas.ts
@@ -903,6 +903,7 @@ export class VideoModes2D implements VideoModes {
     private _context: CanvasRenderingContext2D | null;
     private _left: number;
     private _top: number;
+    private _refreshFlag: boolean = true;
 
     public ready = Promise.resolve();
 
@@ -928,10 +929,7 @@ export class VideoModes2D implements VideoModes {
         mixedDHRMode = this._flag == 2 && doubleHiresMode;
         monoDHRMode = this._flag == 3 && doubleHiresMode;
 
-        this._grs[0].refresh();
-        this._grs[1].refresh();
-        this._hgrs[0].refresh();
-        this._hgrs[1].refresh();
+        this._refreshFlag = true;
     }
 
     refresh() {
@@ -1092,6 +1090,12 @@ export class VideoModes2D implements VideoModes {
         const hgr = this._hgrs[pageMode - 1];
         const gr = this._grs[pageMode - 1];
 
+        if (this._refreshFlag) {
+            hgr.refresh();
+            gr.refresh();
+            this._refreshFlag = false;
+        }
+
         if (altData) {
             blitted = this.updateImage(
                 altData,
diff --git a/js/gl.ts b/js/gl.ts
index da9fe7b..5bd428f 100644
--- a/js/gl.ts
+++ b/js/gl.ts
@@ -603,6 +603,7 @@ export class VideoModesGL implements VideoModes {
     private _displayConfig: screenEmu.DisplayConfiguration;
     private _monoMode: boolean = false;
     private _scanlines: boolean = false;
+    private _refreshFlag: boolean = true;
 
     public ready: Promise<void>
 
@@ -663,10 +664,7 @@ export class VideoModesGL implements VideoModes {
     private _refresh() {
         doubleHiresMode = !an3 && hiresMode && _80colMode;
 
-        this._grs[0].refresh();
-        this._grs[1].refresh();
-        this._hgrs[0].refresh();
-        this._hgrs[1].refresh();
+        this._refreshFlag = true;
 
         if (this._displayConfig) {
             this._displayConfig.videoWhiteOnly = textMode || this._monoMode;
@@ -817,6 +815,12 @@ export class VideoModesGL implements VideoModes {
         const hgr = this._hgrs[pageMode - 1];
         const gr = this._grs[pageMode - 1];
 
+        if (this._refreshFlag) {
+            hgr.refresh();
+            gr.refresh();
+            this._refreshFlag = false;
+        }
+
         if (altData) {
             blitted = this.updateImage(
                 altData,